Contents

The TARDIS has finally brought the Doctor and Sam back to Earth — and straight into danger.

It is 1963. Six very different people have been gathered together for study by parapsychologistCharles Roley in his stately home outside London. All of them claim to have been possessed by the devil, and all have shared similar delusions — they describe the same bizarre "death cave" riddled with demons.

Roley's experiments are having a gradual yet terrifying effect on his subjects, and the Doctor and Sam discover the connections between those tainted with the madness are more disturbing than anyone could guess.

For the Doctor, too, has seen the cave they describe — on a dead world, billions of years ago.

The Doctor inadvertently introduces himself to Rowley as 'Doctor Doctor', prompting Sam to comment on the humorous irony and the Doctor to feign embarrassment as he explains that's why he prefers to be known only as 'Doctor'.